/*******************************************************************************
 * Copyright (c) 2005, 2011 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.ui.text.java;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jdt.core.CompletionProposal;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IMember;
import org.eclipse.jdt.core.JavaModelException;

/**
 * Proposal info that computes the javadoc lazily when it is queried.
 *
 * @since 3.1
 */
public abstract class MemberProposalInfo extends ProposalInfo {
    /* configuration */
    protected final IJavaProject       fJavaProject;
    protected final CompletionProposal fProposal;

    /* cache filled lazily */
    private boolean fJavaElementResolved = false;

    /**
     * Creates a new proposal info.
     *
     * @param project the java project to reference when resolving types
     * @param proposal the proposal to generate information for
     */
    public MemberProposalInfo(IJavaProject project, CompletionProposal proposal) {
        Assert.isNotNull(project);
        Assert.isNotNull(proposal);
        fJavaProject = project;
        fProposal = proposal;
    }

    /**
     * Returns the java element that this computer corresponds to, possibly <code>null</code>.
     *
     * @return the java element that this computer corresponds to, possibly <code>null</code>
     * @throws org.eclipse.jdt.core.JavaModelException if accessing the java model fails
     */
    @Override
    public IJavaElement getJavaElement() throws JavaModelException {
        if (!fJavaElementResolved) {
            fJavaElementResolved = true;
            fElement = resolveMember();
        }
        return fElement;
    }

    /**
     * Resolves the member described by the receiver and returns it if found.
     * Returns <code>null</code> if no corresponding member can be found.
     *
     * @return the resolved member or <code>null</code> if none is found
	 * @throws org.eclipse.jdt.core.JavaModelException if accessing the java model fails
	 */
	protected abstract IMember resolveMember() throws JavaModelException;


}
